Sahih Bukhari Volume 4, Book 51, Hadith Number 20.

Narated By Kab bin Malik : I said, “O Allah’s Apostle! For the acceptance of my repentance I wish to give all my property in charity for Allah’s sake through His Apostle.” He said, “It is better for you to keep some of the property for yourself.” I said, “Then I will keep my share in Khaibar.”